Generalizability of the Self-Care of Diabetes Inventory Across Cultures and Languages: Italy and the United States.

Measuring self-care behaviors is crucial in diabetes research worldwide. Having a common measure of self-care represents an unmet need limiting the development of the science. The Self-Care of Diabetes Inventory was developed to address limitations of previous tools that were not theoretically grounded, strong in psychometrics, and clinically validated. However, the generalizability and comparability of the Self-Care of Diabetes Inventory has not been tested across cultures and languages. The aim of this study was to test the invariance of the Self-Care of Diabetes Inventory measurement model between Italy and the United States. Data from two multicenter cross-sectional studies were used. Two diabetes clinics and two hospitals in Italy and the United States were involved. We enrolled 200 adults in Italy and 226 in the United States, all with a confirmed diagnosis of type 1 or type 2 diabetes. The Self-Care of Diabetes Inventory was used to measure self-care maintenance, monitoring, and management behaviors as described in the middle range theory of self-care of chronic illness. Configural, metric, scalar, and strict invariance were tested for each scale. Three of the four measurement equivalence levels were supported in the three Self-Care of Diabetes Inventory Scales, whereas strict invariance-the highest level-was reached only by the Self-Care Maintenance and Self-Care Monitoring Scales. Clear support for the use of the Self-Care of Diabetes Inventory in diabetes research was provided. Cross-national comparisons of self-care between groups of Italian and U.S. patients are supported, based on the invariance of the measurement model. Aggregation of research data obtained using the Self-Care of Diabetes Inventory across countries could support knowledge development in the field of diabetes self-care.